1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1990, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * Copyright (c) 2019 Andrey V. Elsukov <ae@FreeBSD.org> 7 * 8 * This code is derived from the Stanford/CMU enet packet filter, 9 * (net/enet.c) distributed as part of 4.3BSD, and code contributed 10 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence 11 * Berkeley Laboratory. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 */ 37 38 #include <sys/cdefs.h> 39 #include "opt_bpf.h" 40 #include "opt_netgraph.h" 41 42 #include <sys/param.h> 43 #include <sys/conf.h> 44 #include <sys/fcntl.h> 45 #include <sys/jail.h> 46 #include <sys/ktr.h> 47 #include <sys/lock.h> 48 #include <sys/malloc.h> 49 #include <sys/mbuf.h> 50 #include <sys/mutex.h> 51 #include <sys/time.h> 52 #include <sys/priv.h> 53 #include <sys/proc.h> 54 #include <sys/signalvar.h> 55 #include <sys/filio.h> 56 #include <sys/sockio.h> 57 #include <sys/ttycom.h> 58 #include <sys/uio.h> 59 #include <sys/sysent.h> 60 #include <sys/systm.h> 61 62 #include <sys/file.h> 63 #include <sys/poll.h> 64 #include <sys/proc.h> 65 66 #include <sys/socket.h> 67 68 #include <net/if.h> 69 #include <net/if_var.h> 70 #include <net/if_private.h> 71 #include <net/if_vlan_var.h> 72 #include <net/bpf.h> 73 #include <net/bpf_buffer.h> 74 #ifdef BPF_JITTER 75 #include <net/bpf_jitter.h> 76 #endif 77 #include <net/bpf_zerocopy.h> 78 #include <net/bpfdesc.h> 79 #include <net/vnet.h> 80 81 #include <sys/kernel.h> 82 #include <sys/sysctl.h> 83 84 #include <security/mac/mac_framework.h> 85 86 MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); 87 88 struct bpf_if { 89 struct bpfd_list bif_dlist; /* list of all interfaces */ 90 LIST_ENTRY(bpf_if) bif_next; /* descriptor list */ 91 u_int bif_dlt; /* link layer type */ 92 u_int bif_hdrlen; /* length of link header */ 93 volatile u_int bif_refcnt; 94 struct bpfd_list bif_wlist; /* writer-only list */ 95 const struct bif_methods *bif_methods; 96 void *bif_softc; 97 const char *bif_name; 98 struct epoch_context epoch_ctx; 99 }; 100 101 /* See bpf_peers_present() in bpf.h. */ 102 _Static_assert(offsetof(struct bpf_if, bif_dlist) == 0, 103 "bpf_if shall start with bif_dlist"); 104 105 static inline void 106 bif_attachd(struct bpf_if *bp) 107 { 108 if (bp->bif_methods->bif_attachd != NULL) 109 bp->bif_methods->bif_attachd(bp->bif_softc); 110 } 111 112 static inline void 113 bif_detachd(struct bpf_if *bp) 114 { 115 if (bp->bif_methods->bif_detachd != NULL) 116 bp->bif_methods->bif_detachd(bp->bif_softc); 117 } 118 119 static inline uint32_t 120 bif_wrsize(struct bpf_if *bp) 121 { 122 if (bp->bif_methods->bif_wrsize != NULL) 123 return (bp->bif_methods->bif_wrsize(bp->bif_softc)); 124 else 125 return (0); 126 } 127 128 static inline int 129 bif_promisc(struct bpf_if *bp, bool on) 130 { 131 if (bp->bif_methods->bif_promisc != NULL) 132 return (bp->bif_methods->bif_promisc(bp->bif_softc, on)); 133 else 134 return (0); 135 } 136 137 #ifdef MAC 138 static inline int 139 bif_mac_check_receive(struct bpf_if *bp, struct bpf_d *d) 140 { 141 if (bp->bif_methods->bif_mac_check_receive != NULL) 142 return (bp->bif_methods->bif_mac_check_receive(bp->bif_softc, 143 d)); 144 else 145 return (0); 146 } 147 #endif 148 149 /* 150 * XXXGL: Once we migrate to tapping KPI that would specify packet direction 151 * we no longer need bif_chkdir method. 152 */ 153 static inline bool 154 bpf_chkdir(struct bpf_d *d, struct mbuf *m) 155 { 156 return (d->bd_bif->bif_methods->bif_chkdir(d->bd_bif->bif_softc, m, 157 d->bd_direction)); 158 } 159 160 struct bpf_program_buffer { 161 struct epoch_context epoch_ctx; 162 #ifdef BPF_JITTER 163 bpf_jit_filter *func; 164 #endif 165 void *buffer[0]; 166 }; 167 168 #if defined(DEV_BPF) || defined(NETGRAPH_BPF) 169 170 #define PRINET 26 /* interruptible */ 171 #define BPF_PRIO_MAX 7 172 173 #define SIZEOF_BPF_HDR(type) \ 174 (offsetof(type, bh_hdrlen) + sizeof(((type *)0)->bh_hdrlen)) 175 176 #ifdef COMPAT_FREEBSD32 177 #include <sys/mount.h> 178 #include <compat/freebsd32/freebsd32.h> 179 #define BPF_ALIGNMENT32 sizeof(int32_t) 180 #define BPF_WORDALIGN32(x) roundup2(x, BPF_ALIGNMENT32) 181 182 #ifndef BURN_BRIDGES 183 /* 184 * 32-bit version of structure prepended to each packet. We use this header 185 * instead of the standard one for 32-bit streams. We mark the a stream as 186 * 32-bit the first time we see a 32-bit compat ioctl request. 187 */ 188 struct bpf_hdr32 { 189 struct timeval32 bh_tstamp; /* time stamp */ 190 uint32_t bh_caplen; /* length of captured portion */ 191 uint32_t bh_datalen; /* original length of packet */ 192 uint16_t bh_hdrlen; /* length of bpf header (this struct 193 plus alignment padding) */ 194 }; 195 #endif 196 197 struct bpf_program32 { 198 u_int bf_len; 199 uint32_t bf_insns; 200 }; 201 202 struct bpf_dltlist32 { 203 u_int bfl_len; 204 u_int bfl_list; 205 }; 206 207 #define BIOCSETF32 _IOW('B', 103, struct bpf_program32) 208 #define BIOCSRTIMEOUT32 _IOW('B', 109, struct timeval32) 209 #define BIOCGRTIMEOUT32 _IOR('B', 110, struct timeval32) 210 #define BIOCGDLTLIST32 _IOWR('B', 121, struct bpf_dltlist32) 211 #define BIOCSETWF32 _IOW('B', 123, struct bpf_program32) 212 #define BIOCSETFNR32 _IOW('B', 130, struct bpf_program32) 213 #endif 214 215 #define BPF_LOCK() sx_xlock(&bpf_sx) 216 #define BPF_UNLOCK() sx_xunlock(&bpf_sx) 217 #define BPF_LOCK_ASSERT() sx_assert(&bpf_sx, SA_XLOCKED) 218 /* 219 * bpf_iflist is a list of BPF interface structures, each corresponding to a 220 * specific DLT. The same network interface might have several BPF interface 221 * structures registered by different layers in the stack (i.e., 802.11 222 * frames, ethernet frames, etc). 223 */ 224 VNET_DEFINE_STATIC(LIST_HEAD(, bpf_if), bpf_iflist) = LIST_HEAD_INITIALIZER(); 225 #define V_bpf_iflist VNET(bpf_iflist) 226 static struct sx bpf_sx; /* bpf global lock */ 227 228 static void bpfif_ref(struct bpf_if *); 229 static void bpfif_rele(struct bpf_if *); 230 231 static void bpfd_ref(struct bpf_d *); 232 static void bpfd_rele(struct bpf_d *); 233 static int bpf_attachd(struct bpf_d *d, struct bpf_if *); 234 static void bpf_detachd(struct bpf_d *, bool); 235 static void bpfd_free(epoch_context_t); 236 static void bpf_timed_out(void *); 237 static __inline void 238 bpf_wakeup(struct bpf_d *); 239 static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, 240 void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int), 241 struct bintime *); 242 static void reset_d(struct bpf_d *); 243 static int bpf_getiflist(struct bpf_iflist *); 244 static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); 245 static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); 246 static int bpf_setdlt(struct bpf_d *, u_int); 247 static void filt_bpfdetach(struct knote *); 248 static int filt_bpfread(struct knote *, long); 249 static int filt_bpfwrite(struct knote *, long); 250 static void bpf_drvinit(void *); 251 static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS); 252 253 SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 254 "bpf sysctl"); 255 int bpf_maxinsns = BPF_MAXINSNS; 256 SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW, 257 &bpf_maxinsns, 0, "Maximum bpf program instructions"); 258 static int bpf_zerocopy_enable = 0; 259 SYSCTL_INT(_net_bpf, OID_AUTO, zerocopy_enable, CTLFLAG_RW, 260 &bpf_zerocopy_enable, 0, "Enable new zero-copy BPF buffer sessions"); 261 static SYSCTL_NODE(_net_bpf, OID_AUTO, stats, 262 CTLFLAG_VNET | CTLFLAG_MPSAFE | CTLFLAG_RW, 263 bpf_stats_sysctl, "bpf statistics portal"); 264 265 VNET_DEFINE_STATIC(int, bpf_optimize_writers) = 0; 266 #define V_bpf_optimize_writers VNET(bpf_optimize_writers) 267 SYSCTL_INT(_net_bpf, OID_AUTO, optimize_writers, CTLFLAG_VNET | CTLFLAG_RWTUN, 268 &VNET_NAME(bpf_optimize_writers), 0, 269 "Do not send packets until BPF program is set"); 270 271 static d_open_t bpfopen; 272 static d_read_t bpfread; 273 static d_write_t bpfwrite; 274 static d_ioctl_t bpfioctl; 275 static d_poll_t bpfpoll; 276 static d_kqfilter_t bpfkqfilter; 277 278 static struct cdevsw bpf_cdevsw = { 279 .d_version = D_VERSION, 280 .d_open = bpfopen, 281 .d_read = bpfread, 282 .d_write = bpfwrite, 283 .d_ioctl = bpfioctl, 284 .d_poll = bpfpoll, 285 .d_name = "bpf", 286 .d_kqfilter = bpfkqfilter, 287 }; 288 289 static const struct filterops bpfread_filtops = { 290 .f_isfd = 1, 291 .f_detach = filt_bpfdetach, 292 .f_event = filt_bpfread, 293 .f_copy = knote_triv_copy, 294 }; 295 296 static const struct filterops bpfwrite_filtops = { 297 .f_isfd = 1, 298 .f_detach = filt_bpfdetach, 299 .f_event = filt_bpfwrite, 300 .f_copy = knote_triv_copy, 301 }; 302 303 /* 304 * LOCKING MODEL USED BY BPF 305 * 306 * Locks: 307 * 1) global lock (BPF_LOCK). Sx, used to protect some global counters, 308 * every bpf_iflist changes, serializes ioctl access to bpf descriptors. 309 * 2) Descriptor lock. Mutex, used to protect BPF buffers and various 310 * structure fields used by bpf_*tap* code. 311 * 312 * Lock order: global lock, then descriptor lock. 313 * 314 * There are several possible consumers: 315 * 316 * 1. The kernel registers interface pointer with bpfattach(). 317 * Each call allocates new bpf_if structure, references ifnet pointer 318 * and links bpf_if into bpf_iflist chain. This is protected with global 319 * lock. 320 * 321 * 2. An userland application uses ioctl() call to bpf_d descriptor. 322 * All such call are serialized with global lock. BPF filters can be 323 * changed, but pointer to old filter will be freed using NET_EPOCH_CALL(). 324 * Thus it should be safe for bpf_tap/bpf_mtap* code to do access to 325 * filter pointers, even if change will happen during bpf_tap execution. 326 * Destroying of bpf_d descriptor also is doing using NET_EPOCH_CALL(). 327 * 328 * 3. An userland application can write packets into bpf_d descriptor. 329 * There we need to be sure, that ifnet won't disappear during bpfwrite(). 330 * 331 * 4. The kernel invokes bpf_tap/bpf_mtap* functions. The access to 332 * bif_dlist is protected with net_epoch_preempt section. So, it should 333 * be safe to make access to bpf_d descriptor inside the section. 334 * 335 * 5. The kernel invokes bpfdetach() on interface destroying. All lists 336 * are modified with global lock held and actual free() is done using 337 * NET_EPOCH_CALL(). 338 */ 339 340 static void 341 bpfif_free(epoch_context_t ctx) 342 { 343 struct bpf_if *bp; 344 345 bp = __containerof(ctx, struct bpf_if, epoch_ctx); 346 free(bp, M_BPF); 347 } 348 349 static void 350 bpfif_ref(struct bpf_if *bp) 351 { 352 353 refcount_acquire(&bp->bif_refcnt); 354 } 355 356 static void 357 bpfif_rele(struct bpf_if *bp) 358 { 359 360 if (!refcount_release(&bp->bif_refcnt)) 361 return; 362 NET_EPOCH_CALL(bpfif_free, &bp->epoch_ctx); 363 } 364 365 static void 366 bpfd_ref(struct bpf_d *d) 367 { 368 369 refcount_acquire(&d->bd_refcnt); 370 } 371 372 static void 373 bpfd_rele(struct bpf_d *d) 374 { 375 376 if (!refcount_release(&d->bd_refcnt)) 377 return; 378 NET_EPOCH_CALL(bpfd_free, &d->epoch_ctx); 379 } 380 381 static struct bpf_program_buffer* 382 bpf_program_buffer_alloc(size_t size, int flags) 383 { 384 385 return (malloc(sizeof(struct bpf_program_buffer) + size, 386 M_BPF, flags)); 387 } 388 389 static void 390 bpf_program_buffer_free(epoch_context_t ctx) 391 { 392 struct bpf_program_buffer *ptr; 393 394 ptr = __containerof(ctx, struct bpf_program_buffer, epoch_ctx); 395 #ifdef BPF_JITTER 396 if (ptr->func != NULL) 397 bpf_destroy_jit_filter(ptr->func); 398 #endif 399 free(ptr, M_BPF); 400 } 401 402 /* 403 * Wrapper functions for various buffering methods. If the set of buffer 404 * modes expands, we will probably want to introduce a switch data structure 405 * similar to protosw, et. 406 */ 407 static void 408 bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 409 u_int len) 410 { 411 412 BPFD_LOCK_ASSERT(d); 413 414 switch (d->bd_bufmode) { 415 case BPF_BUFMODE_BUFFER: 416 return (bpf_buffer_append_bytes(d, buf, offset, src, len)); 417 418 case BPF_BUFMODE_ZBUF: 419 counter_u64_add(d->bd_zcopy, 1); 420 return (bpf_zerocopy_append_bytes(d, buf, offset, src, len)); 421 422 default: 423 panic("bpf_buf_append_bytes"); 424 } 425 } 426 427 static void 428 bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 429 u_int len) 430 { 431 432 BPFD_LOCK_ASSERT(d); 433 434 switch (d->bd_bufmode) { 435 case BPF_BUFMODE_BUFFER: 436 return (bpf_buffer_append_mbuf(d, buf, offset, src, len)); 437 438 case BPF_BUFMODE_ZBUF: 439 counter_u64_add(d->bd_zcopy, 1); 440 return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len)); 441 442 default: 443 panic("bpf_buf_append_mbuf"); 444 } 445 } 446 447 /* 448 * This function gets called when the free buffer is re-assigned. 449 */ 450 static void 451 bpf_buf_reclaimed(struct bpf_d *d) 452 { 453 454 BPFD_LOCK_ASSERT(d); 455 456 switch (d->bd_bufmode) { 457 case BPF_BUFMODE_BUFFER: 458 return; 459 460 case BPF_BUFMODE_ZBUF: 461 bpf_zerocopy_buf_reclaimed(d); 462 return; 463 464 default: 465 panic("bpf_buf_reclaimed"); 466 } 467 } 468 469 /* 470 * If the buffer mechanism has a way to decide that a held buffer can be made 471 * free, then it is exposed via the bpf_canfreebuf() interface. (1) is 472 * returned if the buffer can be discarded, (0) is returned if it cannot. 473 */ 474 static int 475 bpf_canfreebuf(struct bpf_d *d) 476 { 477 478 BPFD_LOCK_ASSERT(d); 479 480 switch (d->bd_bufmode) { 481 case BPF_BUFMODE_ZBUF: 482 return (bpf_zerocopy_canfreebuf(d)); 483 } 484 return (0); 485 } 486 487 /* 488 * Allow the buffer model to indicate that the current store buffer is 489 * immutable, regardless of the appearance of space. Return (1) if the 490 * buffer is writable, and (0) if not. 491 */ 492 static int 493 bpf_canwritebuf(struct bpf_d *d) 494 { 495 BPFD_LOCK_ASSERT(d); 496 497 switch (d->bd_bufmode) { 498 case BPF_BUFMODE_ZBUF: 499 return (bpf_zerocopy_canwritebuf(d)); 500 } 501 return (1); 502 } 503 504 /* 505 * Notify buffer model that an attempt to write to the store buffer has 506 * resulted in a dropped packet, in which case the buffer may be considered 507 * full. 508 */ 509 static void 510 bpf_buffull(struct bpf_d *d) 511 { 512 513 BPFD_LOCK_ASSERT(d); 514 515 switch (d->bd_bufmode) { 516 case BPF_BUFMODE_ZBUF: 517 bpf_zerocopy_buffull(d); 518 break; 519 } 520 } 521 522 /* 523 * Notify the buffer model that a buffer has moved into the hold position. 524 */ 525 void 526 bpf_bufheld(struct bpf_d *d) 527 { 528 529 BPFD_LOCK_ASSERT(d); 530 531 switch (d->bd_bufmode) { 532 case BPF_BUFMODE_ZBUF: 533 bpf_zerocopy_bufheld(d); 534 break; 535 } 536 } 537 538 static void 539 bpf_free(struct bpf_d *d) 540 { 541 542 switch (d->bd_bufmode) { 543 case BPF_BUFMODE_BUFFER: 544 return (bpf_buffer_free(d)); 545 546 case BPF_BUFMODE_ZBUF: 547 return (bpf_zerocopy_free(d)); 548 549 default: 550 panic("bpf_buf_free"); 551 } 552 } 553 554 static int 555 bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio) 556 { 557 558 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 559 return (EOPNOTSUPP); 560 return (bpf_buffer_uiomove(d, buf, len, uio)); 561 } 562 563 static int 564 bpf_ioctl_sblen(struct bpf_d *d, u_int *i) 565 { 566 567 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) 568 return (EOPNOTSUPP); 569 return (bpf_buffer_ioctl_sblen(d, i)); 570 } 571 572 static int 573 bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i) 574 { 575 576 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 577 return (EOPNOTSUPP); 578 return (bpf_zerocopy_ioctl_getzmax(td, d, i)); 579 } 580 581 static int 582 bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 583 { 584 585 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 586 return (EOPNOTSUPP); 587 return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz)); 588 } 589 590 static int 591 bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) 592 { 593 594 if (d->bd_bufmode != BPF_BUFMODE_ZBUF) 595 return (EOPNOTSUPP); 596 return (bpf_zerocopy_ioctl_setzbuf(td, d, bz)); 597 } 598 599 /* 600 * Check if we need to upgrade our descriptor @d from write-only mode. 601 */ 602 static int 603 bpf_check_upgrade(u_long cmd, struct bpf_d *d, struct bpf_insn *fcode, 604 int flen) 605 { 606 int is_snap, need_upgrade; 607 608 /* 609 * Check if we've already upgraded or new filter is empty. 610 */ 611 if (d->bd_writer == 0 || fcode == NULL) 612 return (0); 613 614 need_upgrade = 0; 615 616 /* 617 * Check if cmd looks like snaplen setting from 618 * pcap_bpf.c:pcap_open_live(). 619 * Note we're not checking .k value here: 620 * while pcap_open_live() definitely sets to non-zero value, 621 * we'd prefer to treat k=0 (deny ALL) case the same way: e.g. 622 * do not consider upgrading immediately 623 */ 624 if (cmd == BIOCSETF && flen == 1 && 625 fcode[0].code == (BPF_RET | BPF_K)) 626 is_snap = 1; 627 else 628 is_snap = 0; 629 630 if (is_snap == 0) { 631 /* 632 * We're setting first filter and it doesn't look like 633 * setting snaplen. We're probably using bpf directly. 634 * Upgrade immediately. 635 */ 636 need_upgrade = 1; 637 } else { 638 /* 639 * Do not require upgrade by first BIOCSETF 640 * (used to set snaplen) by pcap_open_live(). 641 */ 642 643 if (--d->bd_writer == 0) { 644 /* 645 * First snaplen filter has already 646 * been set. This is probably catch-all 647 * filter 648 */ 649 need_upgrade = 1; 650 } 651 } 652 653 CTR5(KTR_NET, 654 "%s: filter function set by pid %d, " 655 "bd_writer counter %d, snap %d upgrade %d", 656 __func__, d->bd_pid, d->bd_writer, 657 is_snap, need_upgrade); 658 659 return (need_upgrade); 660 } 661 662 /* 663 * Detach a file from its interface. 664 */ 665 static void 666 bpf_detachd(struct bpf_d *d, bool detached_ifp) 667 { 668 struct bpf_if *bp; 669 bool writer; 670 671 BPF_LOCK_ASSERT(); 672 CTR2(KTR_NET, "%s: detach required by pid %d", __func__, d->bd_pid); 673 674 /* Check if descriptor is attached */ 675 if ((bp = d->bd_bif) == NULL) 676 return; 677 678 BPFD_LOCK(d); 679 CK_LIST_REMOVE(d, bd_next); 680 writer = (d->bd_writer > 0); 681 d->bd_bif = NULL; 682 if (detached_ifp) { 683 /* 684 * Notify descriptor as it's detached, so that any 685 * sleepers wake up and get ENXIO. 686 */ 687 bpf_wakeup(d); 688 } 689 BPFD_UNLOCK(d); 690 691 if (!writer) 692 bif_detachd(bp); 693 694 if (d->bd_promisc && !detached_ifp) { 695 d->bd_promisc = 0; 696 (void)bif_promisc(bp, false); 697 } 698 699 bpfif_rele(bp); 700 } 701 702 /* 703 * Close the descriptor by detaching it from its interface, 704 * deallocating its buffers, and marking it free. 705 */ 706 static void 707 bpf_dtor(void *data) 708 { 709 struct bpf_d *d = data; 710 711 BPFD_LOCK(d); 712 if (d->bd_state == BPF_WAITING) 713 callout_stop(&d->bd_callout); 714 d->bd_state = BPF_IDLE; 715 BPFD_UNLOCK(d); 716 funsetown(&d->bd_sigio); 717 BPF_LOCK(); 718 bpf_detachd(d, false); 719 BPF_UNLOCK(); 720 #ifdef MAC 721 mac_bpfdesc_destroy(d); 722 #endif /* MAC */ 723 seldrain(&d->bd_sel); 724 knlist_destroy(&d->bd_sel.si_note); 725 callout_drain(&d->bd_callout); 726 bpfd_rele(d); 727 } 728 729 /* 730 * Open ethernet device. Returns ENXIO for illegal minor device number, 731 * EBUSY if file is open by another process. 732 */ 733 /* ARGSUSED */ 734 static int 735 bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) 736 { 737 struct bpf_d *d; 738 int error; 739 740 d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO); 741 error = devfs_set_cdevpriv(d, bpf_dtor); 742 if (error != 0) { 743 free(d, M_BPF); 744 return (error); 745 } 746 747 /* Setup counters */ 748 d->bd_rcount = counter_u64_alloc(M_WAITOK); 749 d->bd_dcount = counter_u64_alloc(M_WAITOK); 750 d->bd_fcount = counter_u64_alloc(M_WAITOK); 751 d->bd_wcount = counter_u64_alloc(M_WAITOK); 752 d->bd_wfcount = counter_u64_alloc(M_WAITOK); 753 d->bd_wdcount = counter_u64_alloc(M_WAITOK); 754 d->bd_zcopy = counter_u64_alloc(M_WAITOK); 755 756 /* 757 * For historical reasons, perform a one-time initialization call to 758 * the buffer routines, even though we're not yet committed to a 759 * particular buffer method. 760 */ 761 bpf_buffer_init(d); 762 if ((flags & FREAD) == 0) 763 d->bd_writer = 2; 764 d->bd_bufmode = BPF_BUFMODE_BUFFER; 765 d->bd_sig = SIGIO; 766 d->bd_direction = BPF_D_INOUT; 767 refcount_init(&d->bd_refcnt, 1); 768 BPF_PID_REFRESH(d, td); 769 #ifdef MAC 770 mac_bpfdesc_init(d); 771 mac_bpfdesc_create(td->td_ucred, d); 772 #endif 773 mtx_init(&d->bd_lock, devtoname(dev), "bpf cdev lock", MTX_DEF); 774 callout_init_mtx(&d->bd_callout, &d->bd_lock, 0); 775 knlist_init_mtx(&d->bd_sel.si_note, &d->bd_lock); 776 777 /* Disable VLAN pcp tagging. */ 778 d->bd_pcp = 0; 779 780 return (0); 781 } 782 783 /* 784 * bpfread - read next chunk of packets from buffers 785 */ 786 static int 787 bpfread(struct cdev *dev, struct uio *uio, int ioflag) 788 { 789 struct bpf_d *d; 790 int error; 791 int non_block; 792 int timed_out; 793 794 error = devfs_get_cdevpriv((void **)&d); 795 if (error != 0) 796 return (error); 797 798 /* 799 * Restrict application to use a buffer the same size as 800 * as kernel buffers. 801 */ 802 if (uio->uio_resid != d->bd_bufsize) 803 return (EINVAL); 804 805 non_block = ((ioflag & O_NONBLOCK) != 0); 806 807 BPFD_LOCK(d); 808 BPF_PID_REFRESH_CUR(d); 809 if (d->bd_bufmode != BPF_BUFMODE_BUFFER) { 810 BPFD_UNLOCK(d); 811 return (EOPNOTSUPP); 812 } 813 if (d->bd_state == BPF_WAITING) 814 callout_stop(&d->bd_callout); 815 timed_out = (d->bd_state == BPF_TIMED_OUT); 816 d->bd_state = BPF_IDLE; 817 while (d->bd_flags & BPFD_HBUF_INUSE) { 818 error = mtx_sleep(&d->bd_hbuf, &d->bd_lock, PRINET | PCATCH, 819 "bd_hbuf", 0); 820 if (error != 0) { 821 BPFD_UNLOCK(d); 822 return (error); 823 } 824 } 825 /* 826 * If the hold buffer is empty, then do a timed sleep, which 827 * ends when the timeout expires or when enough packets 828 * have arrived to fill the store buffer. 829 */ 830 while (d->bd_hbuf == NULL) { 831 if (d->bd_slen != 0) { 832 /* 833 * A packet(s) either arrived since the previous 834 * read or arrived while we were asleep. 835 */ 836 if ((d->bd_flags & BPFD_IMMEDIATE) || non_block || 837 timed_out) { 838 /* 839 * Rotate the buffers and return what's here 840 * if we are in immediate mode, non-blocking 841 * flag is set, or this descriptor timed out. 842 */ 843 ROTATE_BUFFERS(d); 844 break; 845 } 846 } 847 848 /* 849 * No data is available, check to see if the bpf device 850 * is still pointed at a real interface. If not, return 851 * ENXIO so that the userland process knows to rebind 852 * it before using it again. 853 */ 854 if (d->bd_bif == NULL) { 855 BPFD_UNLOCK(d); 856 return (ENXIO); 857 } 858 859 if (non_block) { 860 BPFD_UNLOCK(d); 861 return (EWOULDBLOCK); 862 } 863 error = msleep(d, &d->bd_lock, PRINET | PCATCH, 864 "bpf", d->bd_rtout); 865 if (error == EINTR || error == ERESTART) { 866 BPFD_UNLOCK(d); 867 return (error); 868 } 869 if (error == EWOULDBLOCK) { 870 /* 871 * On a timeout, return what's in the buffer, 872 * which may be nothing. If there is something 873 * in the store buffer, we can rotate the buffers. 874 */ 875 if (d->bd_hbuf) 876 /* 877 * We filled up the buffer in between 878 * getting the timeout and arriving 879 * here, so we don't need to rotate. 880 */ 881 break; 882 883 if (d->bd_slen == 0) { 884 BPFD_UNLOCK(d); 885 return (0); 886 } 887 ROTATE_BUFFERS(d); 888 break; 889 } 890 } 891 /* 892 * At this point, we know we have something in the hold slot. 893 */ 894 d->bd_flags |= BPFD_HBUF_INUSE; 895 BPFD_UNLOCK(d); 896 897 /* 898 * Move data from hold buffer into user space. 899 * We know the entire buffer is transferred since 900 * we checked above that the read buffer is bpf_bufsize bytes. 901 * 902 * We do not have to worry about simultaneous reads because 903 * we waited for sole access to the hold buffer above. 904 */ 905 error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio); 906 907 BPFD_LOCK(d); 908 if (d->bd_flags & BPFD_HBUF_INUSE) { 909 KASSERT(d->bd_hbuf != NULL, ("bpfread: lost bd_hbuf")); 910 d->bd_fbuf = d->bd_hbuf; 911 d->bd_hbuf = NULL; 912 d->bd_hlen = 0; 913 bpf_buf_reclaimed(d); 914 d->bd_flags &= ~BPFD_HBUF_INUSE; 915 wakeup(&d->bd_hbuf); 916 } 917 BPFD_UNLOCK(d); 918 919 return (error); 920 } 921 922 /* 923 * If there are processes sleeping on this descriptor, wake them up. 924 */ 925 static __inline void 926 bpf_wakeup(struct bpf_d *d) 927 { 928 929 BPFD_LOCK_ASSERT(d); 930 if (d->bd_state == BPF_WAITING) { 931 callout_stop(&d->bd_callout); 932 d->bd_state = BPF_IDLE; 933 } 934 wakeup(d); 935 if ((d->bd_flags & BPFD_ASYNC) && d->bd_sig && d->bd_sigio) 936 pgsigio(&d->bd_sigio, d->bd_sig, 0); 937 938 selwakeuppri(&d->bd_sel, PRINET); 939 KNOTE_LOCKED(&d->bd_sel.si_note, 0); 940 } 941 942 static void 943 bpf_timed_out(void *arg) 944 { 945 struct bpf_d *d = (struct bpf_d *)arg; 946 947 BPFD_LOCK_ASSERT(d); 948 949 if (callout_pending(&d->bd_callout) || 950 !callout_active(&d->bd_callout)) 951 return; 952 if (d->bd_state == BPF_WAITING) { 953 d->bd_state = BPF_TIMED_OUT; 954 if (d->bd_slen != 0) 955 bpf_wakeup(d); 956 } 957 } 958 959 static int 960 bpf_ready(struct bpf_d *d) 961 { 962 963 BPFD_LOCK_ASSERT(d); 964 965 if (!bpf_canfreebuf(d) && d->bd_hlen != 0) 966 return (1); 967 if (((d->bd_flags & BPFD_IMMEDIATE) || d->bd_state == BPF_TIMED_OUT) && 968 d->bd_slen != 0) 969 return (1); 970 return (0); 971 } 972 973 static int 974 bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) 975 { 976 struct epoch_tracker et; 977 struct bpf_if *bp; 978 struct bpf_d *d; 979 struct mbuf *m, *mc; 980 ssize_t len; 981 int error; 982 983 error = devfs_get_cdevpriv((void **)&d); 984 if (error != 0) 985 return (error); 986 987 if (uio->uio_resid == 0) 988 return (0); 989 990 BPFD_LOCK(d); 991 if ((bp = d->bd_bif) == NULL) 992 error = ENXIO; 993 else if (bp->bif_methods->bif_write == NULL) 994 error = EOPNOTSUPP; 995 if (error) { 996 BPFD_UNLOCK(d); 997 counter_u64_add(d->bd_wdcount, 1); 998 return (error); 999 } 1000 bpfd_ref(d); 1001 BPFD_UNLOCK(d); 1002 1003 len = uio->uio_resid; 1004 /* Allocate a mbuf, up to MJUM16BYTES bytes, for our write. */ 1005 m = m_get3(len, M_WAITOK, MT_DATA, M_PKTHDR); 1006 if (m == NULL) { 1007 error = ENOMEM; 1008 goto fail_wref; 1009 } 1010 m->m_pkthdr.len = m->m_len = len; 1011 1012 error = uiomove(mtod(m, u_char *), len, uio); 1013 if (error) 1014 goto fail_wref; 1015 1016 if (bpf_filter(d->bd_wfilter, mtod(m, u_char *), len, len) == 0) { 1017 error = EPERM; 1018 goto fail_wref; 1019 } 1020 1021 if (d->bd_flags & BPFD_FEEDBACK) { 1022 mc = m_dup(m, M_WAITOK); 1023 /* Set M_PROMISC for outgoing packets to be discarded. */ 1024 if (d->bd_direction == BPF_D_INOUT) 1025 m->m_flags |= M_PROMISC; 1026 } else 1027 mc = NULL; 1028 1029 /* XXXGL: should belong to bpf_ifnet.c */ 1030 if (d->bd_pcp != 0) 1031 (void)vlan_set_pcp(m, d->bd_pcp); 1032 1033 BPFD_LOCK(d); 1034 #ifdef MAC 1035 mac_bpfdesc_create_mbuf(d, m); 1036 if (mc != NULL) 1037 mac_bpfdesc_create_mbuf(d, mc); 1038 #endif 1039 /* 1040 * Check that descriptor is still attached to the interface. 1041 * This can happen on bpfdetach() or if other thread did BIOCSDLT. 1042 */ 1043 if (__predict_false(d->bd_bif != bp)) { 1044 BPFD_UNLOCK(d); 1045 m_freem(mc); 1046 error = ENXIO; 1047 goto fail_wref; 1048 } 1049 BPFD_UNLOCK(d); 1050 1051 NET_EPOCH_ENTER(et); 1052 error = bp->bif_methods->bif_write(bp->bif_softc, m, mc, d->bd_flags); 1053 NET_EPOCH_EXIT(et); 1054 if (error) 1055 counter_u64_add(d->bd_wdcount, 1); 1056 else 1057 counter_u64_add(d->bd_wfcount, 1); 1058 bpfd_rele(d); 1059 1060 return (error); 1061 1062 fail_wref: 1063 counter_u64_add(d->bd_wdcount, 1); 1064 bpfd_rele(d); 1065 m_freem(m); 1066 return (error); 1067 } 1068 1069 /* 1070 * Reset a descriptor by flushing its packet buffer and clearing the receive 1071 * and drop counts. This is doable for kernel-only buffers, but with 1072 * zero-copy buffers, we can't write to (or rotate) buffers that are 1073 * currently owned by userspace. It would be nice if we could encapsulate 1074 * this logic in the buffer code rather than here. 1075 */ 1076 static void 1077 reset_d(struct bpf_d *d) 1078 { 1079 1080 BPFD_LOCK_ASSERT(d); 1081 1082 while (d->bd_flags & BPFD_HBUF_INUSE) 1083 mtx_sleep(&d->bd_hbuf, &d->bd_lock, PRINET, "bd_hbuf", 0); 1084 if ((d->bd_hbuf != NULL) && 1085 (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) { 1086 /* Free the hold buffer. */ 1087 d->bd_fbuf = d->bd_hbuf; 1088 d->bd_hbuf = NULL; 1089 d->bd_hlen = 0; 1090 bpf_buf_reclaimed(d); 1091 } 1092 if (bpf_canwritebuf(d)) 1093 d->bd_slen = 0; 1094 counter_u64_zero(d->bd_rcount); 1095 counter_u64_zero(d->bd_dcount); 1096 counter_u64_zero(d->bd_fcount); 1097 counter_u64_zero(d->bd_wcount); 1098 counter_u64_zero(d->bd_wfcount); 1099 counter_u64_zero(d->bd_wdcount); 1100 counter_u64_zero(d->bd_zcopy); 1101 } 1102 1103 /* 1104 * FIONREAD Check for read packet available. 1105 * BIOCGETIFLIST Get list of all tap points. 1106 * BIOCGBLEN Get buffer len [for read()]. 1107 * BIOCSETF Set read filter. 1108 * BIOCSETFNR Set read filter without resetting descriptor. 1109 * BIOCSETWF Set write filter. 1110 * BIOCFLUSH Flush read packet buffer. 1111 * BIOCPROMISC Put interface into promiscuous mode. 1112 * BIOCGDLT Get link layer type. 1113 * BIOCGETIF Get interface name. 1114 * BIOCSETIF Set interface. 1115 * BIOCSRTIMEOUT Set read timeout. 1116 * BIOCGRTIMEOUT Get read timeout. 1117 * BIOCGSTATS Get packet stats. 1118 * BIOCIMMEDIATE Set immediate mode. 1119 * BIOCVERSION Get filter language version. 1120 * BIOCGHDRCMPLT Get "header already complete" flag 1121 * BIOCSHDRCMPLT Set "header already complete" flag 1122 * BIOCGDIRECTION Get packet direction flag 1123 * BIOCSDIRECTION Set packet direction flag 1124 * BIOCGTSTAMP Get time stamp format and resolution. 1125 * BIOCSTSTAMP Set time stamp format and resolution. 1126 * BIOCLOCK Set "locked" flag 1127 * BIOCFEEDBACK Set packet feedback mode. 1128 * BIOCSETZBUF Set current zero-copy buffer locations. 1129 * BIOCGETZMAX Get maximum zero-copy buffer size. 1130 * BIOCROTZBUF Force rotation of zero-copy buffer 1131 * BIOCSETBUFMODE Set buffer mode. 1132 * BIOCGETBUFMODE Get current buffer mode. 1133 * BIOCSETVLANPCP Set VLAN PCP tag. 1134 */ 1135 /* ARGSUSED */ 1136 static int 1137 bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, 1138 struct thread *td) 1139 { 1140 struct bpf_d *d; 1141 int error; 1142 1143 error = devfs_get_cdevpriv((void **)&d); 1144 if (error != 0) 1145 return (error); 1146 1147 /* 1148 * Refresh PID associated with this descriptor. 1149 */ 1150 BPFD_LOCK(d); 1151 BPF_PID_REFRESH(d, td); 1152 if (d->bd_state == BPF_WAITING) 1153 callout_stop(&d->bd_callout); 1154 d->bd_state = BPF_IDLE; 1155 BPFD_UNLOCK(d); 1156 1157 if (d->bd_flags & BPFD_LOCKED) { 1158 switch (cmd) { 1159 case BIOCGETIFLIST: 1160 case BIOCGBLEN: 1161 case BIOCFLUSH: 1162 case BIOCGDLT: 1163 case BIOCGDLTLIST: 1164 #ifdef COMPAT_FREEBSD32 1165 case BIOCGDLTLIST32: 1166 #endif 1167 case BIOCGETIF: 1168 case BIOCGRTIMEOUT: 1169 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1170 case BIOCGRTIMEOUT32: 1171 #endif 1172 case BIOCGSTATS: 1173 case BIOCVERSION: 1174 case BIOCGRSIG: 1175 case BIOCGHDRCMPLT: 1176 case BIOCSTSTAMP: 1177 case BIOCFEEDBACK: 1178 case FIONREAD: 1179 case BIOCLOCK: 1180 case BIOCSRTIMEOUT: 1181 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1182 case BIOCSRTIMEOUT32: 1183 #endif 1184 case BIOCIMMEDIATE: 1185 case TIOCGPGRP: 1186 case BIOCROTZBUF: 1187 break; 1188 default: 1189 return (EPERM); 1190 } 1191 } 1192 #ifdef COMPAT_FREEBSD32 1193 /* 1194 * If we see a 32-bit compat ioctl, mark the stream as 32-bit so 1195 * that it will get 32-bit packet headers. 1196 */ 1197 switch (cmd) { 1198 case BIOCSETF32: 1199 case BIOCSETFNR32: 1200 case BIOCSETWF32: 1201 case BIOCGDLTLIST32: 1202 case BIOCGRTIMEOUT32: 1203 case BIOCSRTIMEOUT32: 1204 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 1205 BPFD_LOCK(d); 1206 d->bd_compat32 = 1; 1207 BPFD_UNLOCK(d); 1208 } 1209 } 1210 #endif 1211 1212 CURVNET_SET(TD_TO_VNET(td)); 1213 switch (cmd) { 1214 default: 1215 error = EINVAL; 1216 break; 1217 1218 /* 1219 * Check for read packet available. 1220 */ 1221 case FIONREAD: 1222 { 1223 int n; 1224 1225 BPFD_LOCK(d); 1226 n = d->bd_slen; 1227 while (d->bd_flags & BPFD_HBUF_INUSE) 1228 mtx_sleep(&d->bd_hbuf, &d->bd_lock, 1229 PRINET, "bd_hbuf", 0); 1230 if (d->bd_hbuf) 1231 n += d->bd_hlen; 1232 BPFD_UNLOCK(d); 1233 1234 *(int *)addr = n; 1235 break; 1236 } 1237 /* 1238 * Get list of all tap points. 1239 */ 1240 case BIOCGETIFLIST: 1241 error = bpf_getiflist((struct bpf_iflist *)addr); 1242 break; 1243 1244 /* 1245 * Get buffer len [for read()]. 1246 */ 1247 case BIOCGBLEN: 1248 BPFD_LOCK(d); 1249 *(u_int *)addr = d->bd_bufsize; 1250 BPFD_UNLOCK(d); 1251 break; 1252 1253 /* 1254 * Set buffer length. 1255 */ 1256 case BIOCSBLEN: 1257 error = bpf_ioctl_sblen(d, (u_int *)addr); 1258 break; 1259 1260 /* 1261 * Set link layer read filter. 1262 */ 1263 case BIOCSETF: 1264 case BIOCSETFNR: 1265 case BIOCSETWF: 1266 #ifdef COMPAT_FREEBSD32 1267 case BIOCSETF32: 1268 case BIOCSETFNR32: 1269 case BIOCSETWF32: 1270 #endif 1271 error = bpf_setf(d, (struct bpf_program *)addr, cmd); 1272 break; 1273 1274 /* 1275 * Flush read packet buffer. 1276 */ 1277 case BIOCFLUSH: 1278 BPFD_LOCK(d); 1279 reset_d(d); 1280 BPFD_UNLOCK(d); 1281 break; 1282 1283 /* 1284 * Put interface into promiscuous mode. 1285 */ 1286 case BIOCPROMISC: 1287 BPF_LOCK(); 1288 if (d->bd_bif == NULL) { 1289 /* 1290 * No interface attached yet. 1291 */ 1292 error = EINVAL; 1293 } else if (d->bd_promisc == 0) { 1294 struct bpf_if *bp = d->bd_bif; 1295 1296 if ((error = bif_promisc(bp, true)) == 0) 1297 d->bd_promisc = 1; 1298 } 1299 BPF_UNLOCK(); 1300 break; 1301 1302 /* 1303 * Get current data link type. 1304 */ 1305 case BIOCGDLT: 1306 BPF_LOCK(); 1307 if (d->bd_bif == NULL) 1308 error = EINVAL; 1309 else 1310 *(u_int *)addr = d->bd_bif->bif_dlt; 1311 BPF_UNLOCK(); 1312 break; 1313 1314 /* 1315 * Get a list of supported data link types. 1316 */ 1317 #ifdef COMPAT_FREEBSD32 1318 case BIOCGDLTLIST32: 1319 { 1320 struct bpf_dltlist32 *list32; 1321 struct bpf_dltlist dltlist; 1322 1323 list32 = (struct bpf_dltlist32 *)addr; 1324 dltlist.bfl_len = list32->bfl_len; 1325 dltlist.bfl_list = PTRIN(list32->bfl_list); 1326 BPF_LOCK(); 1327 if (d->bd_bif == NULL) 1328 error = EINVAL; 1329 else { 1330 error = bpf_getdltlist(d, &dltlist); 1331 if (error == 0) 1332 list32->bfl_len = dltlist.bfl_len; 1333 } 1334 BPF_UNLOCK(); 1335 break; 1336 } 1337 #endif 1338 1339 case BIOCGDLTLIST: 1340 BPF_LOCK(); 1341 if (d->bd_bif == NULL) 1342 error = EINVAL; 1343 else 1344 error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); 1345 BPF_UNLOCK(); 1346 break; 1347 1348 /* 1349 * Set data link type. 1350 */ 1351 case BIOCSDLT: 1352 BPF_LOCK(); 1353 if (d->bd_bif == NULL) 1354 error = EINVAL; 1355 else 1356 error = bpf_setdlt(d, *(u_int *)addr); 1357 BPF_UNLOCK(); 1358 break; 1359 1360 /* 1361 * Get interface name. 1362 */ 1363 case BIOCGETIF: 1364 BPF_LOCK(); 1365 if (d->bd_bif == NULL) 1366 error = EINVAL; 1367 else { 1368 struct bpf_if *const bp = d->bd_bif; 1369 struct ifreq *const ifr = (struct ifreq *)addr; 1370 1371 strlcpy(ifr->ifr_name, bp->bif_name, 1372 sizeof(ifr->ifr_name)); 1373 } 1374 BPF_UNLOCK(); 1375 break; 1376 1377 /* 1378 * Set interface. 1379 */ 1380 case BIOCSETIF: { 1381 struct ifreq *const ifr = (struct ifreq *)addr; 1382 struct bpf_if *bp; 1383 1384 /* 1385 * Behavior here depends on the buffering model. If we're 1386 * using kernel memory buffers, then we can allocate them here. 1387 * If we're using zero-copy, then the user process must have 1388 * registered buffers by the time we get here. 1389 */ 1390 BPFD_LOCK(d); 1391 if (d->bd_bufmode == BPF_BUFMODE_BUFFER && 1392 d->bd_sbuf == NULL) { 1393 u_int size; 1394 1395 size = d->bd_bufsize; 1396 BPFD_UNLOCK(d); 1397 error = bpf_buffer_ioctl_sblen(d, &size); 1398 if (error != 0) 1399 break; 1400 } else 1401 BPFD_UNLOCK(d); 1402 BPF_LOCK(); 1403 /* 1404 * Look through attached interfaces for the named one. 1405 */ 1406 LIST_FOREACH(bp, &V_bpf_iflist, bif_next) { 1407 if (strncmp(ifr->ifr_name, bp->bif_name, 1408 sizeof(ifr->ifr_name)) == 0) 1409 break; 1410 } 1411 if (bp != NULL) 1412 error = bpf_attachd(d, bp); 1413 else 1414 error = ENXIO; 1415 BPF_UNLOCK(); 1416 break; 1417 } 1418 /* 1419 * Set read timeout. 1420 */ 1421 case BIOCSRTIMEOUT: 1422 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1423 case BIOCSRTIMEOUT32: 1424 #endif 1425 { 1426 struct timeval *tv = (struct timeval *)addr; 1427 #if defined(COMPAT_FREEBSD32) 1428 struct timeval32 *tv32; 1429 struct timeval tv64; 1430 1431 if (cmd == BIOCSRTIMEOUT32) { 1432 tv32 = (struct timeval32 *)addr; 1433 tv = &tv64; 1434 tv->tv_sec = tv32->tv_sec; 1435 tv->tv_usec = tv32->tv_usec; 1436 } else 1437 #endif 1438 tv = (struct timeval *)addr; 1439 1440 /* 1441 * Subtract 1 tick from tvtohz() since this isn't 1442 * a one-shot timer. 1443 */ 1444 if ((error = itimerfix(tv)) == 0) 1445 d->bd_rtout = tvtohz(tv) - 1; 1446 break; 1447 } 1448 1449 /* 1450 * Get read timeout. 1451 */ 1452 case BIOCGRTIMEOUT: 1453 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1454 case BIOCGRTIMEOUT32: 1455 #endif 1456 { 1457 struct timeval *tv; 1458 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1459 struct timeval32 *tv32; 1460 struct timeval tv64; 1461 1462 if (cmd == BIOCGRTIMEOUT32) 1463 tv = &tv64; 1464 else 1465 #endif 1466 tv = (struct timeval *)addr; 1467 1468 tv->tv_sec = d->bd_rtout / hz; 1469 tv->tv_usec = (d->bd_rtout % hz) * tick; 1470 #if defined(COMPAT_FREEBSD32) && defined(__amd64__) 1471 if (cmd == BIOCGRTIMEOUT32) { 1472 tv32 = (struct timeval32 *)addr; 1473 tv32->tv_sec = tv->tv_sec; 1474 tv32->tv_usec = tv->tv_usec; 1475 } 1476 #endif 1477 1478 break; 1479 } 1480 1481 /* 1482 * Get packet stats. 1483 */ 1484 case BIOCGSTATS: 1485 { 1486 struct bpf_stat *bs = (struct bpf_stat *)addr; 1487 1488 /* XXXCSJP overflow */ 1489 bs->bs_recv = (u_int)counter_u64_fetch(d->bd_rcount); 1490 bs->bs_drop = (u_int)counter_u64_fetch(d->bd_dcount); 1491 break; 1492 } 1493 1494 /* 1495 * Set immediate mode. 1496 */ 1497 case BIOCIMMEDIATE: 1498 BPFD_LOCK(d); 1499 d->bd_flags |= *(u_int *)addr ? BPFD_IMMEDIATE : 0; 1500 BPFD_UNLOCK(d); 1501 break; 1502 1503 case BIOCVERSION: 1504 { 1505 struct bpf_version *bv = (struct bpf_version *)addr; 1506 1507 bv->bv_major = BPF_MAJOR_VERSION; 1508 bv->bv_minor = BPF_MINOR_VERSION; 1509 break; 1510 } 1511 1512 /* 1513 * Get "header already complete" flag 1514 */ 1515 case BIOCGHDRCMPLT: 1516 BPFD_LOCK(d); 1517 *(u_int *)addr = d->bd_flags & BPFD_HDRCMPLT ? 1 : 0; 1518 BPFD_UNLOCK(d); 1519 break; 1520 1521 /* 1522 * Set "header already complete" flag 1523 */ 1524 case BIOCSHDRCMPLT: 1525 BPFD_LOCK(d); 1526 d->bd_flags |= *(u_int *)addr ? BPFD_HDRCMPLT : 0; 1527 BPFD_UNLOCK(d); 1528 break; 1529 1530 /* 1531 * Get packet direction flag 1532 */ 1533 case BIOCGDIRECTION: 1534 BPFD_LOCK(d); 1535 *(u_int *)addr = d->bd_direction; 1536 BPFD_UNLOCK(d); 1537 break; 1538 1539 /* 1540 * Set packet direction flag 1541 */ 1542 case BIOCSDIRECTION: 1543 { 1544 u_int direction; 1545 1546 direction = *(u_int *)addr; 1547 switch (direction) { 1548 case BPF_D_IN: 1549 case BPF_D_INOUT: 1550 case BPF_D_OUT: 1551 BPFD_LOCK(d); 1552 d->bd_direction = direction; 1553 BPFD_UNLOCK(d); 1554 break; 1555 default: 1556 error = EINVAL; 1557 } 1558 } 1559 break; 1560 1561 /* 1562 * Get packet timestamp format and resolution. 1563 */ 1564 case BIOCGTSTAMP: 1565 BPFD_LOCK(d); 1566 *(u_int *)addr = d->bd_tstamp; 1567 BPFD_UNLOCK(d); 1568 break; 1569 1570 /* 1571 * Set packet timestamp format and resolution. 1572 */ 1573 case BIOCSTSTAMP: 1574 { 1575 u_int func; 1576 1577 func = *(u_int *)addr; 1578 if (BPF_T_VALID(func)) 1579 d->bd_tstamp = func; 1580 else 1581 error = EINVAL; 1582 } 1583 break; 1584 1585 case BIOCFEEDBACK: 1586 BPFD_LOCK(d); 1587 d->bd_flags |= *(u_int *)addr ? BPFD_FEEDBACK : 0; 1588 BPFD_UNLOCK(d); 1589 break; 1590 1591 case BIOCLOCK: 1592 BPFD_LOCK(d); 1593 d->bd_flags |= BPFD_LOCKED; 1594 BPFD_UNLOCK(d); 1595 break; 1596 1597 case FIONBIO: /* Non-blocking I/O */ 1598 break; 1599 1600 case FIOASYNC: /* Send signal on receive packets */ 1601 BPFD_LOCK(d); 1602 d->bd_flags |= *(u_int *)addr ? BPFD_ASYNC : 0; 1603 BPFD_UNLOCK(d); 1604 break; 1605 1606 case FIOSETOWN: 1607 /* 1608 * XXX: Add some sort of locking here? 1609 * fsetown() can sleep. 1610 */ 1611 error = fsetown(*(int *)addr, &d->bd_sigio); 1612 break; 1613 1614 case FIOGETOWN: 1615 BPFD_LOCK(d); 1616 *(int *)addr = fgetown(&d->bd_sigio); 1617 BPFD_UNLOCK(d); 1618 break; 1619 1620 /* This is deprecated, FIOSETOWN should be used instead. */ 1621 case TIOCSPGRP: 1622 error = fsetown(-(*(int *)addr), &d->bd_sigio); 1623 break; 1624 1625 /* This is deprecated, FIOGETOWN should be used instead. */ 1626 case TIOCGPGRP: 1627 *(int *)addr = -fgetown(&d->bd_sigio); 1628 break; 1629 1630 case BIOCSRSIG: /* Set receive signal */ 1631 { 1632 u_int sig; 1633 1634 sig = *(u_int *)addr; 1635 1636 if (sig >= NSIG) 1637 error = EINVAL; 1638 else { 1639 BPFD_LOCK(d); 1640 d->bd_sig = sig; 1641 BPFD_UNLOCK(d); 1642 } 1643 break; 1644 } 1645 case BIOCGRSIG: 1646 BPFD_LOCK(d); 1647 *(u_int *)addr = d->bd_sig; 1648 BPFD_UNLOCK(d); 1649 break; 1650 1651 case BIOCGETBUFMODE: 1652 BPFD_LOCK(d); 1653 *(u_int *)addr = d->bd_bufmode; 1654 BPFD_UNLOCK(d); 1655 break; 1656 1657 case BIOCSETBUFMODE: 1658 /* 1659 * Allow the buffering mode to be changed as long as we 1660 * haven't yet committed to a particular mode. Our 1661 * definition of commitment, for now, is whether or not a 1662 * buffer has been allocated or an interface attached, since 1663 * that's the point where things get tricky. 1664 */ 1665 switch (*(u_int *)addr) { 1666 case BPF_BUFMODE_BUFFER: 1667 break; 1668 1669 case BPF_BUFMODE_ZBUF: 1670 if (bpf_zerocopy_enable) 1671 break; 1672 /* FALLSTHROUGH */ 1673 1674 default: 1675 CURVNET_RESTORE(); 1676 return (EINVAL); 1677 } 1678 1679 BPFD_LOCK(d); 1680 if (d->bd_sbuf != NULL || d->bd_hbuf != NULL || 1681 d->bd_fbuf != NULL || d->bd_bif != NULL) { 1682 BPFD_UNLOCK(d); 1683 CURVNET_RESTORE(); 1684 return (EBUSY); 1685 } 1686 d->bd_bufmode = *(u_int *)addr; 1687 BPFD_UNLOCK(d); 1688 break; 1689 1690 case BIOCGETZMAX: 1691 error = bpf_ioctl_getzmax(td, d, (size_t *)addr); 1692 break; 1693 1694 case BIOCSETZBUF: 1695 error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr); 1696 break; 1697 1698 case BIOCROTZBUF: 1699 error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr); 1700 break; 1701 1702 case BIOCSETVLANPCP: 1703 { 1704 u_int pcp; 1705 1706 pcp = *(u_int *)addr; 1707 if (pcp > BPF_PRIO_MAX || pcp < 0) { 1708 error = EINVAL; 1709 break; 1710 } 1711 d->bd_pcp = pcp; 1712 break; 1713 } 1714 } 1715 CURVNET_RESTORE(); 1716 return (error); 1717 } 1718 1719 /* 1720 * Return list of available tapping points, or report how much space is 1721 * required for a successful return. 1722 */ 1723 static int 1724 bpf_getiflist(struct bpf_iflist *bi) 1725 { 1726 struct bpf_if *bp; 1727 u_int allsize, size, cnt; 1728 char *uaddr; 1729 1730 BPF_LOCK(); 1731 1732 cnt = allsize = size = 0; 1733 LIST_FOREACH(bp, &V_bpf_iflist, bif_next) { 1734 allsize += strlen(bp->bif_name) + 1; 1735 if (++cnt == bi->bi_count) 1736 size = allsize; 1737 } 1738 if (size == 0) 1739 size = allsize; 1740 1741 if (bi->bi_size == 0) { 1742 BPF_UNLOCK(); 1743 bi->bi_size = size; 1744 bi->bi_count = cnt; 1745 return (0); 1746 } else if (bi->bi_size < size) { 1747 BPF_UNLOCK(); 1748 return (ENOSPC); 1749 } 1750 1751 uaddr = bi->bi_ubuf; 1752 cnt = 0; 1753 LIST_FOREACH(bp, &V_bpf_iflist, bif_next) { 1754 u_int len; 1755 int error; 1756 1757 len = strlen(bp->bif_name) + 1; 1758 if ((error = copyout(bp->bif_name, uaddr, len)) != 0) { 1759 BPF_UNLOCK(); 1760 return (error); 1761 } 1762 if (++cnt == bi->bi_count) 1763 break; 1764 uaddr += len; 1765 } 1766 BPF_UNLOCK(); 1767 bi->bi_count = cnt; 1768 1769 return (0); 1770 } 1771 1772 /* 1773 * Set d's packet filter program to fp. If this file already has a filter, 1774 * free it and replace it. Returns EINVAL for bogus requests. 1775 * 1776 * Note we use global lock here to serialize bpf_setf() and bpf_setif() 1777 * calls. 1778 */ 1779 static int 1780 bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) 1781 { 1782 #ifdef COMPAT_FREEBSD32 1783 struct bpf_program fp_swab; 1784 struct bpf_program32 *fp32; 1785 #endif 1786 struct bpf_program_buffer *fcode; 1787 struct bpf_insn *filter; 1788 #ifdef BPF_JITTER 1789 bpf_jit_filter *jfunc; 1790 #endif 1791 size_t size; 1792 u_int flen; 1793 bool track_event; 1794 1795 #ifdef COMPAT_FREEBSD32 1796 switch (cmd) { 1797 case BIOCSETF32: 1798 case BIOCSETWF32: 1799 case BIOCSETFNR32: 1800 fp32 = (struct bpf_program32 *)fp; 1801 fp_swab.bf_len = fp32->bf_len; 1802 fp_swab.bf_insns = 1803 (struct bpf_insn *)(uintptr_t)fp32->bf_insns; 1804 fp = &fp_swab; 1805 switch (cmd) { 1806 case BIOCSETF32: 1807 cmd = BIOCSETF; 1808 break; 1809 case BIOCSETWF32: 1810 cmd = BIOCSETWF; 1811 break; 1812 } 1813 break; 1814 } 1815 #endif 1816 1817 filter = NULL; 1818 #ifdef BPF_JITTER 1819 jfunc = NULL; 1820 #endif 1821 /* 1822 * Check new filter validness before acquiring any locks. 1823 * Allocate memory for new filter, if needed. 1824 */ 1825 flen = fp->bf_len; 1826 if (flen > bpf_maxinsns || (fp->bf_insns == NULL && flen != 0)) 1827 return (EINVAL); 1828 size = flen * sizeof(*fp->bf_insns); 1829 if (size > 0) { 1830 /* We're setting up new filter. Copy and check actual data. */ 1831 fcode = bpf_program_buffer_alloc(size, M_WAITOK); 1832 filter = (struct bpf_insn *)fcode->buffer; 1833 if (copyin(fp->bf_insns, filter, size) != 0 || 1834 !bpf_validate(filter, flen)) { 1835 free(fcode, M_BPF); 1836 return (EINVAL); 1837 } 1838 #ifdef BPF_JITTER 1839 if (cmd != BIOCSETWF) { 1840 /* 1841 * Filter is copied inside fcode and is 1842 * perfectly valid. 1843 */ 1844 jfunc = bpf_jitter(filter, flen); 1845 } 1846 #endif 1847 } 1848 1849 track_event = false; 1850 fcode = NULL; 1851 1852 BPF_LOCK(); 1853 BPFD_LOCK(d); 1854 /* Set up new filter. */ 1855 if (cmd == BIOCSETWF) { 1856 if (d->bd_wfilter != NULL) { 1857 fcode = __containerof((void *)d->bd_wfilter, 1858 struct bpf_program_buffer, buffer); 1859 #ifdef BPF_JITTER 1860 fcode->func = NULL; 1861 #endif 1862 } 1863 d->bd_wfilter = filter; 1864 } else { 1865 if (d->bd_rfilter != NULL) { 1866 fcode = __containerof((void *)d->bd_rfilter, 1867 struct bpf_program_buffer, buffer); 1868 #ifdef BPF_JITTER 1869 fcode->func = d->bd_bfilter; 1870 #endif 1871 } 1872 d->bd_rfilter = filter; 1873 #ifdef BPF_JITTER 1874 d->bd_bfilter = jfunc; 1875 #endif 1876 if (cmd == BIOCSETF) 1877 reset_d(d); 1878 1879 if (bpf_check_upgrade(cmd, d, filter, flen) != 0) { 1880 /* 1881 * Filter can be set several times without 1882 * specifying interface. In this case just mark d 1883 * as reader. 1884 */ 1885 d->bd_writer = 0; 1886 if (d->bd_bif != NULL) { 1887 /* 1888 * Remove descriptor from writers-only list 1889 * and add it to active readers list. 1890 */ 1891 CK_LIST_REMOVE(d, bd_next); 1892 CK_LIST_INSERT_HEAD(&d->bd_bif->bif_dlist, 1893 d, bd_next); 1894 CTR2(KTR_NET, 1895 "%s: upgrade required by pid %d", 1896 __func__, d->bd_pid); 1897 track_event = true; 1898 } 1899 } 1900 } 1901 BPFD_UNLOCK(d); 1902 1903 if (fcode != NULL) 1904 NET_EPOCH_CALL(bpf_program_buffer_free, &fcode->epoch_ctx); 1905 1906 if (track_event) 1907 bif_attachd(d->bd_bif); 1908 1909 BPF_UNLOCK(); 1910 return (0); 1911 } 1912 1913 /* 1914 * Attach descriptor to a tap point, possibly detaching from the old one, 1915 * reset the counters. 1916 * XXXGL: this KPI is subject to change 1917 */ 1918 static int 1919 bpf_attachd(struct bpf_d *d, struct bpf_if *bp) 1920 { 1921 bool writer; 1922 1923 BPF_LOCK_ASSERT(); 1924 1925 /* 1926 * At this point, we expect the buffer is already allocated. If not, 1927 * return an error. 1928 */ 1929 switch (d->bd_bufmode) { 1930 case BPF_BUFMODE_BUFFER: 1931 case BPF_BUFMODE_ZBUF: 1932 if (d->bd_sbuf == NULL) 1933 return (EINVAL); 1934 break; 1935 1936 default: 1937 panic("%s: bufmode %d", __func__, d->bd_bufmode); 1938 } 1939 1940 if (bp == d->bd_bif) { 1941 BPFD_LOCK(d); 1942 reset_d(d); 1943 BPFD_UNLOCK(d); 1944 return (0); 1945 } else if (d->bd_bif != NULL) 1946 bpf_detachd(d, false); 1947 1948 /* 1949 * Save sysctl value to protect from sysctl change between reads. 1950 */ 1951 writer = V_bpf_optimize_writers || (d->bd_writer > 0); 1952 1953 /* 1954 * Point d at bp, and add d to the interface's list. 1955 * Since there are many applications using BPF for 1956 * sending raw packets only (dhcpd, cdpd are good examples) 1957 * we can delay adding d to the list of active listeners until 1958 * some filter is configured. 1959 */ 1960 BPFD_LOCK(d); 1961 /* 1962 * Hold reference to bpif while descriptor uses this interface. 1963 */ 1964 bpfif_ref(bp); 1965 d->bd_bif = bp; 1966 if (writer) { 1967 /* Add to writers-only list */ 1968 CK_LIST_INSERT_HEAD(&bp->bif_wlist, d, bd_next); 1969 /* 1970 * We decrement bd_writer on every filter set operation. 1971 * First BIOCSETF is done by pcap_open_live() to set up 1972 * snap length. After that application usually sets its own 1973 * filter. 1974 */ 1975 d->bd_writer = 2; 1976 } else 1977 CK_LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); 1978 1979 reset_d(d); 1980 1981 /* Trigger EVFILT_WRITE events. */ 1982 bpf_wakeup(d); 1983 1984 BPFD_UNLOCK(d); 1985 1986 CTR3(KTR_NET, "%s: called by pid %d, adding to %s list", 1987 __func__, d->bd_pid, d->bd_writer ? "writer" : "active"); 1988 1989 if (!writer) 1990 bif_attachd(bp); 1991 1992 return (0); 1993 } 1994 1995 /* 1996 * Support for select() and poll() system calls 1997 * 1998 * Return true iff the specific operation will not block indefinitely. 1999 * Otherwise, return false but make a note that a selwakeup() must be done. 2000 */ 2001 static int 2002 bpfpoll(struct cdev *dev, int events, struct thread *td) 2003 { 2004 struct bpf_d *d; 2005 int revents; 2006 2007 if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL) 2008 return (events & 2009 (POLLHUP | POLLIN | POLLRDNORM | POLLOUT | POLLWRNORM)); 2010 2011 /* 2012 * Refresh PID associated with this descriptor. 2013 */ 2014 revents = events & (POLLOUT | POLLWRNORM); 2015 BPFD_LOCK(d); 2016 BPF_PID_REFRESH(d, td); 2017 if (events & (POLLIN | POLLRDNORM)) { 2018 if (bpf_ready(d)) 2019 revents |= events & (POLLIN | POLLRDNORM); 2020 else { 2021 selrecord(td, &d->bd_sel); 2022 /* Start the read timeout if necessary. */ 2023 if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2024 callout_reset(&d->bd_callout, d->bd_rtout, 2025 bpf_timed_out, d); 2026 d->bd_state = BPF_WAITING; 2027 } 2028 } 2029 } 2030 BPFD_UNLOCK(d); 2031 return (revents); 2032 } 2033 2034 /* 2035 * Support for kevent() system call. Register EVFILT_READ filters and 2036 * reject all others. 2037 */ 2038 int 2039 bpfkqfilter(struct cdev *dev, struct knote *kn) 2040 { 2041 struct bpf_d *d; 2042 2043 if (devfs_get_cdevpriv((void **)&d) != 0) 2044 return (1); 2045 2046 switch (kn->kn_filter) { 2047 case EVFILT_READ: 2048 kn->kn_fop = &bpfread_filtops; 2049 break; 2050 2051 case EVFILT_WRITE: 2052 kn->kn_fop = &bpfwrite_filtops; 2053 break; 2054 2055 default: 2056 return (1); 2057 } 2058 2059 /* 2060 * Refresh PID associated with this descriptor. 2061 */ 2062 BPFD_LOCK(d); 2063 BPF_PID_REFRESH_CUR(d); 2064 kn->kn_hook = d; 2065 knlist_add(&d->bd_sel.si_note, kn, 1); 2066 BPFD_UNLOCK(d); 2067 2068 return (0); 2069 } 2070 2071 static void 2072 filt_bpfdetach(struct knote *kn) 2073 { 2074 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2075 2076 knlist_remove(&d->bd_sel.si_note, kn, 0); 2077 } 2078 2079 static int 2080 filt_bpfread(struct knote *kn, long hint) 2081 { 2082 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2083 int ready; 2084 2085 BPFD_LOCK_ASSERT(d); 2086 ready = bpf_ready(d); 2087 if (ready) { 2088 kn->kn_data = d->bd_slen; 2089 /* 2090 * Ignore the hold buffer if it is being copied to user space. 2091 */ 2092 if (!(d->bd_flags & BPFD_HBUF_INUSE) && d->bd_hbuf) 2093 kn->kn_data += d->bd_hlen; 2094 } else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { 2095 callout_reset(&d->bd_callout, d->bd_rtout, 2096 bpf_timed_out, d); 2097 d->bd_state = BPF_WAITING; 2098 } 2099 2100 return (ready); 2101 } 2102 2103 static int 2104 filt_bpfwrite(struct knote *kn, long hint) 2105 { 2106 struct bpf_d *d = (struct bpf_d *)kn->kn_hook; 2107 2108 BPFD_LOCK_ASSERT(d); 2109 2110 if (d->bd_bif == NULL) { 2111 kn->kn_data = 0; 2112 return (0); 2113 } else { 2114 kn->kn_data = bif_wrsize(d->bd_bif); 2115 return (1); 2116 } 2117 } 2118 2119 #define BPF_TSTAMP_NONE 0 2120 #define BPF_TSTAMP_FAST 1 2121 #define BPF_TSTAMP_NORMAL 2 2122 #define BPF_TSTAMP_EXTERN 3 2123 2124 static int 2125 bpf_ts_quality(int tstype) 2126 { 2127 2128 if (tstype == BPF_T_NONE) 2129 return (BPF_TSTAMP_NONE); 2130 if ((tstype & BPF_T_FAST) != 0) 2131 return (BPF_TSTAMP_FAST); 2132 2133 return (BPF_TSTAMP_NORMAL); 2134 } 2135 2136 static int 2137 bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m) 2138 { 2139 struct timespec ts; 2140 struct m_tag *tag; 2141 int quality; 2142 2143 quality = bpf_ts_quality(tstype); 2144 if (quality == BPF_TSTAMP_NONE) 2145 return (quality); 2146 2147 if (m != NULL) { 2148 if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR | M_TSTMP)) { 2149 mbuf_tstmp2timespec(m, &ts); 2150 timespec2bintime(&ts, bt); 2151 return (BPF_TSTAMP_EXTERN); 2152 } 2153 tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL); 2154 if (tag != NULL) { 2155 *bt = *(struct bintime *)(tag + 1); 2156 return (BPF_TSTAMP_EXTERN); 2157 } 2158 } 2159 if (quality == BPF_TSTAMP_NORMAL) 2160 binuptime(bt); 2161 else 2162 getbinuptime(bt); 2163 2164 return (quality); 2165 } 2166 2167 /* 2168 * Incoming linkage from device drivers. Process the packet pkt, of length 2169 * pktlen, which is stored in a contiguous buffer. The packet is parsed 2170 * by each process' filter, and if accepted, stashed into the corresponding 2171 * buffer. 2172 */ 2173 void 2174 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2175 { 2176 struct epoch_tracker et; 2177 struct bintime bt; 2178 struct bpf_d *d; 2179 #ifdef BPF_JITTER 2180 bpf_jit_filter *bf; 2181 #endif 2182 u_int slen; 2183 int gottime; 2184 2185 gottime = BPF_TSTAMP_NONE; 2186 NET_EPOCH_ENTER(et); 2187 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2188 counter_u64_add(d->bd_rcount, 1); 2189 /* 2190 * NB: We don't check the direction here since there 2191 * is no way for the caller to indiciate to us whether this 2192 * packet is inbound or outbound. In the bpf_mtap() routines, 2193 * we use the interface pointers on the mbuf to figure it out. 2194 */ 2195 #ifdef BPF_JITTER 2196 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2197 if (bf != NULL) 2198 slen = (*(bf->func))(pkt, pktlen, pktlen); 2199 else 2200 #endif 2201 slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); 2202 if (slen != 0) { 2203 /* 2204 * Filter matches. Let's to acquire write lock. 2205 */ 2206 BPFD_LOCK(d); 2207 counter_u64_add(d->bd_fcount, 1); 2208 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2209 gottime = bpf_gettime(&bt, d->bd_tstamp, 2210 NULL); 2211 #ifdef MAC 2212 if (bif_mac_check_receive(bp, d) == 0) 2213 #endif 2214 catchpacket(d, pkt, pktlen, slen, 2215 bpf_append_bytes, &bt); 2216 BPFD_UNLOCK(d); 2217 } 2218 } 2219 NET_EPOCH_EXIT(et); 2220 } 2221 2222 void 2223 bpf_tap_if(if_t ifp, u_char *pkt, u_int pktlen) 2224 { 2225 if (bpf_peers_present(ifp->if_bpf)) 2226 bpf_tap(ifp->if_bpf, pkt, pktlen); 2227 } 2228 2229 /* 2230 * Incoming linkage from device drivers, when packet is in an mbuf chain. 2231 * Locking model is explained in bpf_tap(). 2232 */ 2233 void 2234 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 2235 { 2236 struct epoch_tracker et; 2237 struct bintime bt; 2238 struct bpf_d *d; 2239 #ifdef BPF_JITTER 2240 bpf_jit_filter *bf; 2241 #endif 2242 u_int pktlen, slen; 2243 int gottime; 2244 2245 /* Skip outgoing duplicate packets. */ 2246 if ((m->m_flags & M_PROMISC) != 0 && m_rcvif(m) == NULL) { 2247 m->m_flags &= ~M_PROMISC; 2248 return; 2249 } 2250 2251 pktlen = m_length(m, NULL); 2252 gottime = BPF_TSTAMP_NONE; 2253 2254 NET_EPOCH_ENTER(et); 2255 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2256 if (bpf_chkdir(d, m)) 2257 continue; 2258 counter_u64_add(d->bd_rcount, 1); 2259 #ifdef BPF_JITTER 2260 bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; 2261 /* XXX We cannot handle multiple mbufs. */ 2262 if (bf != NULL && m->m_next == NULL) 2263 slen = (*(bf->func))(mtod(m, u_char *), pktlen, 2264 pktlen); 2265 else 2266 #endif 2267 slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); 2268 if (slen != 0) { 2269 BPFD_LOCK(d); 2270 2271 counter_u64_add(d->bd_fcount, 1); 2272 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2273 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2274 #ifdef MAC 2275 if (bif_mac_check_receive(bp, d) == 0) 2276 #endif 2277 catchpacket(d, (u_char *)m, pktlen, slen, 2278 bpf_append_mbuf, &bt); 2279 BPFD_UNLOCK(d); 2280 } 2281 } 2282 NET_EPOCH_EXIT(et); 2283 } 2284 2285 void 2286 bpf_mtap_if(if_t ifp, struct mbuf *m) 2287 { 2288 if (bpf_peers_present(ifp->if_bpf)) { 2289 M_ASSERTVALID(m); 2290 bpf_mtap(ifp->if_bpf, m); 2291 } 2292 } 2293 2294 /* 2295 * Incoming linkage from device drivers, when packet is in 2296 * an mbuf chain and to be prepended by a contiguous header. 2297 */ 2298 void 2299 bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) 2300 { 2301 struct epoch_tracker et; 2302 struct bintime bt; 2303 struct mbuf mb; 2304 struct bpf_d *d; 2305 u_int pktlen, slen; 2306 int gottime; 2307 2308 /* Skip outgoing duplicate packets. */ 2309 if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { 2310 m->m_flags &= ~M_PROMISC; 2311 return; 2312 } 2313 2314 pktlen = m_length(m, NULL); 2315 /* 2316 * Craft on-stack mbuf suitable for passing to bpf_filter. 2317 * Note that we cut corners here; we only setup what's 2318 * absolutely needed--this mbuf should never go anywhere else. 2319 */ 2320 mb.m_flags = 0; 2321 mb.m_next = m; 2322 mb.m_data = data; 2323 mb.m_len = dlen; 2324 pktlen += dlen; 2325 2326 gottime = BPF_TSTAMP_NONE; 2327 2328 NET_EPOCH_ENTER(et); 2329 CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { 2330 if (bpf_chkdir(d, m)) 2331 continue; 2332 counter_u64_add(d->bd_rcount, 1); 2333 slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); 2334 if (slen != 0) { 2335 BPFD_LOCK(d); 2336 2337 counter_u64_add(d->bd_fcount, 1); 2338 if (gottime < bpf_ts_quality(d->bd_tstamp)) 2339 gottime = bpf_gettime(&bt, d->bd_tstamp, m); 2340 #ifdef MAC 2341 if (bif_mac_check_receive(bp, d) == 0) 2342 #endif 2343 catchpacket(d, (u_char *)&mb, pktlen, slen, 2344 bpf_append_mbuf, &bt); 2345 BPFD_UNLOCK(d); 2346 } 2347 } 2348 NET_EPOCH_EXIT(et); 2349 } 2350 2351 void 2352 bpf_mtap2_if(if_t ifp, void *data, u_int dlen, struct mbuf *m) 2353 { 2354 if (bpf_peers_present(ifp->if_bpf)) { 2355 M_ASSERTVALID(m); 2356 bpf_mtap2(ifp->if_bpf, data, dlen, m); 2357 } 2358 } 2359 2360 #undef BPF_TSTAMP_NONE 2361 #undef BPF_TSTAMP_FAST 2362 #undef BPF_TSTAMP_NORMAL 2363 #undef BPF_TSTAMP_EXTERN 2364 2365 static int 2366 bpf_hdrlen(struct bpf_d *d) 2367 { 2368 int hdrlen; 2369 2370 hdrlen = d->bd_bif->bif_hdrlen; 2371 #ifndef BURN_BRIDGES 2372 if (d->bd_tstamp == BPF_T_NONE || 2373 BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME) 2374 #ifdef COMPAT_FREEBSD32 2375 if (d->bd_compat32) 2376 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32); 2377 else 2378 #endif 2379 hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr); 2380 else 2381 #endif 2382 hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr); 2383 #ifdef COMPAT_FREEBSD32 2384 if (d->bd_compat32) 2385 hdrlen = BPF_WORDALIGN32(hdrlen); 2386 else 2387 #endif 2388 hdrlen = BPF_WORDALIGN(hdrlen); 2389 2390 return (hdrlen - d->bd_bif->bif_hdrlen); 2391 } 2392 2393 static void 2394 bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype) 2395 { 2396 struct bintime bt2, boottimebin; 2397 struct timeval tsm; 2398 struct timespec tsn; 2399 2400 if ((tstype & BPF_T_MONOTONIC) == 0) { 2401 bt2 = *bt; 2402 getboottimebin(&boottimebin); 2403 bintime_add(&bt2, &boottimebin); 2404 bt = &bt2; 2405 } 2406 switch (BPF_T_FORMAT(tstype)) { 2407 case BPF_T_MICROTIME: 2408 bintime2timeval(bt, &tsm); 2409 ts->bt_sec = tsm.tv_sec; 2410 ts->bt_frac = tsm.tv_usec; 2411 break; 2412 case BPF_T_NANOTIME: 2413 bintime2timespec(bt, &tsn); 2414 ts->bt_sec = tsn.tv_sec; 2415 ts->bt_frac = tsn.tv_nsec; 2416 break; 2417 case BPF_T_BINTIME: 2418 ts->bt_sec = bt->sec; 2419 ts->bt_frac = bt->frac; 2420 break; 2421 } 2422 } 2423 2424 /* 2425 * Move the packet data from interface memory (pkt) into the 2426 * store buffer. "cpfn" is the routine called to do the actual data 2427 * transfer. bcopy is passed in to copy contiguous chunks, while 2428 * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case, 2429 * pkt is really an mbuf. 2430 */ 2431 static void 2432 catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, 2433 void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int), 2434 struct bintime *bt) 2435 { 2436 static char zeroes[BPF_ALIGNMENT]; 2437 struct bpf_xhdr hdr; 2438 #ifndef BURN_BRIDGES 2439 struct bpf_hdr hdr_old; 2440 #ifdef COMPAT_FREEBSD32 2441 struct bpf_hdr32 hdr32_old; 2442 #endif 2443 #endif 2444 int caplen, curlen, hdrlen, pad, totlen; 2445 int do_wakeup = 0; 2446 int do_timestamp; 2447 int tstype; 2448 2449 BPFD_LOCK_ASSERT(d); 2450 if (d->bd_bif == NULL) { 2451 /* Descriptor was detached in concurrent thread */ 2452 counter_u64_add(d->bd_dcount, 1); 2453 return; 2454 } 2455 2456 /* 2457 * Detect whether user space has released a buffer back to us, and if 2458 * so, move it from being a hold buffer to a free buffer. This may 2459 * not be the best place to do it (for example, we might only want to 2460 * run this check if we need the space), but for now it's a reliable 2461 * spot to do it. 2462 */ 2463 if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) { 2464 d->bd_fbuf = d->bd_hbuf; 2465 d->bd_hbuf = NULL; 2466 d->bd_hlen = 0; 2467 bpf_buf_reclaimed(d); 2468 } 2469 2470 /* 2471 * Figure out how many bytes to move. If the packet is 2472 * greater or equal to the snapshot length, transfer that 2473 * much. Otherwise, transfer the whole packet (unless 2474 * we hit the buffer size limit). 2475 */ 2476 hdrlen = bpf_hdrlen(d); 2477 totlen = hdrlen + min(snaplen, pktlen); 2478 if (totlen > d->bd_bufsize) 2479 totlen = d->bd_bufsize; 2480 2481 /* 2482 * Round up the end of the previous packet to the next longword. 2483 * 2484 * Drop the packet if there's no room and no hope of room 2485 * If the packet would overflow the storage buffer or the storage 2486 * buffer is considered immutable by the buffer model, try to rotate 2487 * the buffer and wakeup pending processes. 2488 */ 2489 #ifdef COMPAT_FREEBSD32 2490 if (d->bd_compat32) 2491 curlen = BPF_WORDALIGN32(d->bd_slen); 2492 else 2493 #endif 2494 curlen = BPF_WORDALIGN(d->bd_slen); 2495 if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) { 2496 if (d->bd_fbuf == NULL) { 2497 /* 2498 * There's no room in the store buffer, and no 2499 * prospect of room, so drop the packet. Notify the 2500 * buffer model. 2501 */ 2502 bpf_buffull(d); 2503 counter_u64_add(d->bd_dcount, 1); 2504 return; 2505 } 2506 KASSERT(!(d->bd_flags & BPFD_HBUF_INUSE), 2507 ("hold buffer is in use")); 2508 ROTATE_BUFFERS(d); 2509 do_wakeup = 1; 2510 curlen = 0; 2511 } else { 2512 if ((d->bd_flags & BPFD_IMMEDIATE) || 2513 d->bd_state == BPF_TIMED_OUT) { 2514 /* 2515 * Immediate mode is set, or the read timeout has 2516 * already expired during a select call. A packet 2517 * arrived, so the reader should be woken up. 2518 */ 2519 do_wakeup = 1; 2520 } 2521 pad = curlen - d->bd_slen; 2522 KASSERT(pad >= 0 && pad <= sizeof(zeroes), 2523 ("%s: invalid pad byte count %d", __func__, pad)); 2524 if (pad > 0) { 2525 /* Zero pad bytes. */ 2526 bpf_append_bytes(d, d->bd_sbuf, d->bd_slen, zeroes, 2527 pad); 2528 } 2529 } 2530 2531 caplen = totlen - hdrlen; 2532 tstype = d->bd_tstamp; 2533 do_timestamp = tstype != BPF_T_NONE; 2534 #ifndef BURN_BRIDGES 2535 if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) { 2536 struct bpf_ts ts; 2537 if (do_timestamp) 2538 bpf_bintime2ts(bt, &ts, tstype); 2539 #ifdef COMPAT_FREEBSD32 2540 if (d->bd_compat32) { 2541 bzero(&hdr32_old, sizeof(hdr32_old)); 2542 if (do_timestamp) { 2543 hdr32_old.bh_tstamp.tv_sec = ts.bt_sec; 2544 hdr32_old.bh_tstamp.tv_usec = ts.bt_frac; 2545 } 2546 hdr32_old.bh_datalen = pktlen; 2547 hdr32_old.bh_hdrlen = hdrlen; 2548 hdr32_old.bh_caplen = caplen; 2549 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old, 2550 sizeof(hdr32_old)); 2551 goto copy; 2552 } 2553 #endif 2554 bzero(&hdr_old, sizeof(hdr_old)); 2555 if (do_timestamp) { 2556 hdr_old.bh_tstamp.tv_sec = ts.bt_sec; 2557 hdr_old.bh_tstamp.tv_usec = ts.bt_frac; 2558 } 2559 hdr_old.bh_datalen = pktlen; 2560 hdr_old.bh_hdrlen = hdrlen; 2561 hdr_old.bh_caplen = caplen; 2562 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old, 2563 sizeof(hdr_old)); 2564 goto copy; 2565 } 2566 #endif 2567 2568 /* 2569 * Append the bpf header. Note we append the actual header size, but 2570 * move forward the length of the header plus padding. 2571 */ 2572 bzero(&hdr, sizeof(hdr)); 2573 if (do_timestamp) 2574 bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype); 2575 hdr.bh_datalen = pktlen; 2576 hdr.bh_hdrlen = hdrlen; 2577 hdr.bh_caplen = caplen; 2578 bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr)); 2579 2580 /* 2581 * Copy the packet data into the store buffer and update its length. 2582 */ 2583 #ifndef BURN_BRIDGES 2584 copy: 2585 #endif 2586 (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen); 2587 d->bd_slen = curlen + totlen; 2588 2589 if (do_wakeup) 2590 bpf_wakeup(d); 2591 } 2592 2593 /* 2594 * Free buffers currently in use by a descriptor. 2595 * Called on close. 2596 */ 2597 static void 2598 bpfd_free(epoch_context_t ctx) 2599 { 2600 struct bpf_d *d; 2601 struct bpf_program_buffer *p; 2602 2603 /* 2604 * We don't need to lock out interrupts since this descriptor has 2605 * been detached from its interface and it yet hasn't been marked 2606 * free. 2607 */ 2608 d = __containerof(ctx, struct bpf_d, epoch_ctx); 2609 bpf_free(d); 2610 if (d->bd_rfilter != NULL) { 2611 p = __containerof((void *)d->bd_rfilter, 2612 struct bpf_program_buffer, buffer); 2613 #ifdef BPF_JITTER 2614 p->func = d->bd_bfilter; 2615 #endif 2616 bpf_program_buffer_free(&p->epoch_ctx); 2617 } 2618 if (d->bd_wfilter != NULL) { 2619 p = __containerof((void *)d->bd_wfilter, 2620 struct bpf_program_buffer, buffer); 2621 #ifdef BPF_JITTER 2622 p->func = NULL; 2623 #endif 2624 bpf_program_buffer_free(&p->epoch_ctx); 2625 } 2626 2627 mtx_destroy(&d->bd_lock); 2628 counter_u64_free(d->bd_rcount); 2629 counter_u64_free(d->bd_dcount); 2630 counter_u64_free(d->bd_fcount); 2631 counter_u64_free(d->bd_wcount); 2632 counter_u64_free(d->bd_wfcount); 2633 counter_u64_free(d->bd_wdcount); 2634 counter_u64_free(d->bd_zcopy); 2635 free(d, M_BPF); 2636 } 2637 2638 /* 2639 * Attach a tap point to bpf. 2640 * XXX: with current KPI it is consumer's responsibility to avoid duplicates. 2641 */ 2642 struct bpf_if * 2643 bpf_attach(const char *name, u_int dlt, u_int hdrlen, 2644 const struct bif_methods *methods, void *sc) 2645 { 2646 struct bpf_if *bp; 2647 2648 bp = malloc(sizeof(*bp), M_BPF, M_WAITOK | M_ZERO); 2649 2650 CK_LIST_INIT(&bp->bif_dlist); 2651 CK_LIST_INIT(&bp->bif_wlist); 2652 bp->bif_dlt = dlt; 2653 bp->bif_hdrlen = hdrlen; 2654 bp->bif_softc = sc; 2655 bp->bif_name = name; 2656 bp->bif_methods = methods; 2657 refcount_init(&bp->bif_refcnt, 1); 2658 BPF_LOCK(); 2659 LIST_INSERT_HEAD(&V_bpf_iflist, bp, bif_next); 2660 BPF_UNLOCK(); 2661 2662 return (bp); 2663 } 2664 2665 #ifdef VIMAGE 2666 /* 2667 * Detach descriptors on interface's vmove event. 2668 * XXXGL: shouldn't be a special case, but a full detach. 2669 */ 2670 void 2671 bpf_ifdetach(struct ifnet *ifp) 2672 { 2673 struct bpf_if *bp; 2674 struct bpf_d *d; 2675 2676 BPF_LOCK(); 2677 LIST_FOREACH(bp, &V_bpf_iflist, bif_next) { 2678 /* XXXGL: assuming softc is ifnet here */ 2679 if (bp->bif_softc != ifp) 2680 continue; 2681 2682 /* Detach common descriptors */ 2683 while ((d = CK_LIST_FIRST(&bp->bif_dlist)) != NULL) { 2684 bpf_detachd(d, true); 2685 } 2686 2687 /* Detach writer-only descriptors */ 2688 while ((d = CK_LIST_FIRST(&bp->bif_wlist)) != NULL) { 2689 bpf_detachd(d, true); 2690 } 2691 } 2692 BPF_UNLOCK(); 2693 } 2694 #endif 2695 2696 /* 2697 * Detach bpf tap point. This involves detaching each descriptor associated 2698 * with the interface. Notify each descriptor as it's detached so that any 2699 * sleepers wake up and get ENXIO. 2700 */ 2701 void 2702 bpf_detach(struct bpf_if *bp) 2703 { 2704 struct bpf_d *d; 2705 2706 BPF_LOCK(); 2707 LIST_REMOVE(bp, bif_next); 2708 2709 CTR3(KTR_NET, "%s: sheduling free for encap %d for bp %p", 2710 __func__, bp->bif_dlt, bp); 2711 2712 /* Detach common descriptors */ 2713 while ((d = CK_LIST_FIRST(&bp->bif_dlist)) != NULL) { 2714 bpf_detachd(d, true); 2715 } 2716 2717 /* Detach writer-only descriptors */ 2718 while ((d = CK_LIST_FIRST(&bp->bif_wlist)) != NULL) { 2719 bpf_detachd(d, true); 2720 } 2721 bpfif_rele(bp); 2722 BPF_UNLOCK(); 2723 } 2724 2725 #ifdef VIMAGE 2726 /* 2727 * Move bpf to a different VNET. This KPI is a crutch to support if_vmove 2728 * and is not supposed to be used anywhere else. 2729 */ 2730 void 2731 bpf_vmove(struct bpf_if *bp) 2732 { 2733 2734 BPF_LOCK(); 2735 LIST_REMOVE(bp, bif_next); 2736 LIST_INSERT_HEAD(&V_bpf_iflist, bp, bif_next); 2737 BPF_UNLOCK(); 2738 } 2739 #endif 2740 2741 bool 2742 bpf_peers_present_if(struct ifnet *ifp) 2743 { 2744 return (bpf_peers_present(ifp->if_bpf)); 2745 } 2746 2747 /* 2748 * Get a list of available data link type of the tap point. If a tap point 2749 * attaches more than one time, it is supposed to attach with different DLTs 2750 * but with the same name pointer. 2751 */ 2752 static int 2753 bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) 2754 { 2755 const char *name; 2756 struct bpf_if *bp; 2757 u_int *lst; 2758 int error, n, n1; 2759 2760 BPF_LOCK_ASSERT(); 2761 2762 name = d->bd_bif->bif_name; 2763 n1 = 0; 2764 LIST_FOREACH(bp, &V_bpf_iflist, bif_next) { 2765 if (bp->bif_name == name) 2766 n1++; 2767 } 2768 if (bfl->bfl_list == NULL) { 2769 bfl->bfl_len = n1; 2770 return (0); 2771 } 2772 if (n1 > bfl->bfl_len) 2773 return (ENOMEM); 2774 2775 lst = malloc(n1 * sizeof(u_int), M_TEMP, M_WAITOK); 2776 n = 0; 2777 LIST_FOREACH(bp, &V_bpf_iflist, bif_next) { 2778 if (bp->bif_name != name) 2779 continue; 2780 lst[n++] = bp->bif_dlt; 2781 } 2782 error = copyout(lst, bfl->bfl_list, sizeof(u_int) * n); 2783 free(lst, M_TEMP); 2784 bfl->bfl_len = n; 2785 return (error); 2786 } 2787 2788 /* 2789 * Set the data link type of a BPF descriptor. The convention is that 2790 * application first do BIOCSETIF and then BIOCSETDLT, thus the descriptor 2791 * is supposed to be already attached. Only one kernel facility provides 2792 * tapping points with same name but different DLT - ieee80211_radiotap. 2793 * 2794 * XXXGL: this function definitely looks suspicious, e.g. it clearly doesn't 2795 * clear promisc on the old bpf_if. The convention about reference counting 2796 * is also unclear. 2797 */ 2798 static int 2799 bpf_setdlt(struct bpf_d *d, u_int dlt) 2800 { 2801 int error, opromisc; 2802 const char *name; 2803 struct bpf_if *bp; 2804 2805 BPF_LOCK_ASSERT(); 2806 MPASS(d->bd_bif != NULL); 2807 2808 /* 2809 * It is safe to check bd_bif without BPFD_LOCK, it can not be 2810 * changed while we hold global lock. 2811 */ 2812 if (d->bd_bif->bif_dlt == dlt) 2813 return (0); 2814 2815 name = d->bd_bif->bif_name; 2816 LIST_FOREACH(bp, &V_bpf_iflist, bif_next) { 2817 if (bp->bif_name == name && bp->bif_dlt == dlt) 2818 break; 2819 } 2820 if (bp == NULL) 2821 return (EINVAL); 2822 2823 opromisc = d->bd_promisc; 2824 bpf_detachd(d, false); 2825 bpf_attachd(d, bp); 2826 if (opromisc) { 2827 error = bp->bif_methods->bif_promisc(bp->bif_softc, true); 2828 if (error) 2829 printf("%s: bif_promisc on %s failed (%d)\n", 2830 __func__, bp->bif_name, error); 2831 else 2832 d->bd_promisc = 1; 2833 } 2834 return (0); 2835 } 2836 2837 static void 2838 bpf_drvinit(void *unused) 2839 { 2840 struct cdev *dev; 2841 2842 sx_init(&bpf_sx, "bpf global lock"); 2843 dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf"); 2844 /* For compatibility */ 2845 make_dev_alias(dev, "bpf0"); 2846 } 2847 2848 /* 2849 * Zero out the various packet counters associated with all of the bpf 2850 * descriptors. At some point, we will probably want to get a bit more 2851 * granular and allow the user to specify descriptors to be zeroed. 2852 */ 2853 static void 2854 bpf_zero_counters(void) 2855 { 2856 struct bpf_if *bp; 2857 struct bpf_d *bd; 2858 2859 BPF_LOCK(); 2860 /* 2861 * We are protected by global lock here, interfaces and 2862 * descriptors can not be deleted while we hold it. 2863 */ 2864 LIST_FOREACH(bp, &V_bpf_iflist, bif_next) { 2865 CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2866 counter_u64_zero(bd->bd_rcount); 2867 counter_u64_zero(bd->bd_dcount); 2868 counter_u64_zero(bd->bd_fcount); 2869 counter_u64_zero(bd->bd_wcount); 2870 counter_u64_zero(bd->bd_wfcount); 2871 counter_u64_zero(bd->bd_zcopy); 2872 } 2873 } 2874 BPF_UNLOCK(); 2875 } 2876 2877 /* 2878 * Fill filter statistics 2879 */ 2880 static void 2881 bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) 2882 { 2883 2884 BPF_LOCK_ASSERT(); 2885 bzero(d, sizeof(*d)); 2886 d->bd_structsize = sizeof(*d); 2887 d->bd_immediate = bd->bd_flags & BPFD_IMMEDIATE ? 1 : 0; 2888 d->bd_promisc = bd->bd_promisc; 2889 d->bd_hdrcmplt = bd->bd_flags & BPFD_HDRCMPLT ? 1 : 0; 2890 d->bd_direction = bd->bd_direction; 2891 d->bd_feedback = bd->bd_flags & BPFD_FEEDBACK ? 1 : 0; 2892 d->bd_async = bd->bd_flags & BPFD_ASYNC ? 1 : 0; 2893 d->bd_rcount = counter_u64_fetch(bd->bd_rcount); 2894 d->bd_dcount = counter_u64_fetch(bd->bd_dcount); 2895 d->bd_fcount = counter_u64_fetch(bd->bd_fcount); 2896 d->bd_sig = bd->bd_sig; 2897 d->bd_slen = bd->bd_slen; 2898 d->bd_hlen = bd->bd_hlen; 2899 d->bd_bufsize = bd->bd_bufsize; 2900 d->bd_pid = bd->bd_pid; 2901 strlcpy(d->bd_ifname, bd->bd_bif->bif_name, sizeof(d->bd_ifname)); 2902 d->bd_locked = bd->bd_flags & BPFD_LOCKED ? 1 : 0; 2903 d->bd_wcount = counter_u64_fetch(bd->bd_wcount); 2904 d->bd_wdcount = counter_u64_fetch(bd->bd_wdcount); 2905 d->bd_wfcount = counter_u64_fetch(bd->bd_wfcount); 2906 d->bd_zcopy = counter_u64_fetch(bd->bd_zcopy); 2907 d->bd_bufmode = bd->bd_bufmode; 2908 } 2909 2910 /* 2911 * Handle `netstat -B' stats request 2912 */ 2913 static int 2914 bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) 2915 { 2916 static const struct xbpf_d zerostats; 2917 struct xbpf_d *xbdbuf, *xbd, tempstats; 2918 u_int bpfd_cnt, index; 2919 int error; 2920 struct bpf_if *bp; 2921 struct bpf_d *bd; 2922 2923 /* 2924 * XXX This is not technically correct. It is possible for non 2925 * privileged users to open bpf devices. It would make sense 2926 * if the users who opened the devices were able to retrieve 2927 * the statistics for them, too. 2928 */ 2929 error = priv_check(req->td, PRIV_NET_BPF); 2930 if (error) 2931 return (error); 2932 /* 2933 * Check to see if the user is requesting that the counters be 2934 * zeroed out. Explicitly check that the supplied data is zeroed, 2935 * as we aren't allowing the user to set the counters currently. 2936 */ 2937 if (req->newptr != NULL) { 2938 if (req->newlen != sizeof(tempstats)) 2939 return (EINVAL); 2940 memset(&tempstats, 0, sizeof(tempstats)); 2941 error = SYSCTL_IN(req, &tempstats, sizeof(tempstats)); 2942 if (error) 2943 return (error); 2944 if (bcmp(&tempstats, &zerostats, sizeof(tempstats)) != 0) 2945 return (EINVAL); 2946 bpf_zero_counters(); 2947 return (0); 2948 } 2949 bpfd_cnt = 0; 2950 BPF_LOCK(); 2951 LIST_FOREACH(bp, &V_bpf_iflist, bif_next) { 2952 CK_LIST_FOREACH(bd, &bp->bif_wlist, bd_next) 2953 bpfd_cnt++; 2954 CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) 2955 bpfd_cnt++; 2956 } 2957 if (bpfd_cnt == 0 || req->oldptr == NULL) { 2958 BPF_UNLOCK(); 2959 return (SYSCTL_OUT(req, 0, bpfd_cnt * sizeof(*xbd))); 2960 } 2961 if (req->oldlen < bpfd_cnt * sizeof(*xbd)) { 2962 BPF_UNLOCK(); 2963 return (ENOMEM); 2964 } 2965 xbdbuf = malloc(bpfd_cnt * sizeof(*xbd), M_BPF, M_WAITOK); 2966 index = 0; 2967 LIST_FOREACH(bp, &V_bpf_iflist, bif_next) { 2968 /* Send writers-only first */ 2969 CK_LIST_FOREACH(bd, &bp->bif_wlist, bd_next) { 2970 MPASS(index <= bpfd_cnt); 2971 xbd = &xbdbuf[index++]; 2972 bpfstats_fill_xbpf(xbd, bd); 2973 } 2974 CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { 2975 MPASS(index <= bpfd_cnt); 2976 xbd = &xbdbuf[index++]; 2977 bpfstats_fill_xbpf(xbd, bd); 2978 } 2979 } 2980 BPF_UNLOCK(); 2981 error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); 2982 free(xbdbuf, M_BPF); 2983 return (error); 2984 } 2985 2986 SYSINIT(bpfdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, bpf_drvinit, NULL); 2987 2988 #else /* !DEV_BPF && !NETGRAPH_BPF */ 2989 2990 /* 2991 * NOP stubs to allow bpf-using drivers to load and function. 2992 * 2993 * A 'better' implementation would allow the core bpf functionality 2994 * to be loaded at runtime. 2995 */ 2996 2997 void 2998 bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) 2999 { 3000 } 3001 3002 void 3003 bpf_tap_if(if_t ifp, u_char *pkt, u_int pktlen) 3004 { 3005 } 3006 3007 void 3008 bpf_mtap(struct bpf_if *bp, struct mbuf *m) 3009 { 3010 } 3011 3012 void 3013 bpf_mtap_if(if_t ifp, struct mbuf *m) 3014 { 3015 } 3016 3017 void 3018 bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) 3019 { 3020 } 3021 3022 void 3023 bpf_mtap2_if(if_t ifp, void *data, u_int dlen, struct mbuf *m) 3024 { 3025 } 3026 3027 void 3028 bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) 3029 { 3030 static const struct bpfd_list dead_bpf_if = CK_LIST_HEAD_INITIALIZER(); 3031 3032 ifp->if_bpf = __DECONST(struct bpf_if *, &dead_bpf_if); 3033 } 3034 3035 void 3036 bpfdetach(struct ifnet *ifp) 3037 { 3038 } 3039 3040 bool 3041 bpf_peers_present_if(struct ifnet *ifp) 3042 { 3043 return (false); 3044 } 3045 3046 u_int 3047 bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) 3048 { 3049 return (-1); /* "no filter" behaviour */ 3050 } 3051 3052 int 3053 bpf_validate(const struct bpf_insn *f, int len) 3054 { 3055 return (0); /* false */ 3056 } 3057 3058 #endif /* !DEV_BPF && !NETGRAPH_BPF */ 3059